A whirlpool of frigid, dense air known as a "polar vortex" descended Monday into much of the United States, pummeling Michigan with a dangerous cold that shut down universities, forced a delay in a Detroit bankruptcy case, and prompted Gov. Rick Snyder to activated the state's Emergency Operations Center to respond to requests for help across the state.

Flights scheduled this morning to depart to many airports around the country have been canceled; about a quarter of the flights scheduled to leave Detroit Metropolitan Airport between 6 and 9 a.m. this morning were canceled.

Detroit city offices were to be open today, according to a city press release.

Many state offices are closed today, including those in Lansing. Snyder said residents should heed advisories to stay off the roads if possible.

For most of Michigan, the subzero temperatures were moving in behind another winter wallop: snow and high winds that made traveling treacherous.

The National Weather Service says that as of Monday morning 16.2 inches of snow fell in Flint, 15.5 inches fell north of Jackson, 15.4 inches fell at Howell and 15 inches was reported north of Battle Creek. Temperatures are to drop late Monday or early Tuesday as low as minus 15. Temperatures Monday morning are in the teens in Detroit. A reading of 22 degrees below zero was reported in the Upper Peninsula community of Ironwood.

Hearing delayed in Detroit bankruptcy case

Winter weather has delayed closing arguments in a bankruptcy court hearing on an agreement by Detroit to pay off banks and settle millions of dollars in debt tied to an interest rate swaps deal.

Bankruptcy court in Detroit was shut today amid severe weather.

Emergency manager Kevyn Orr testified Friday that the proposal to terminate the deal with UBS and Bank of America for $165 million is best for the city.

The city pledged casino tax revenue in 2009 as collateral to avoid defaulting on pension debt payments. The swaps allowed Detroit to get fixed interest rates on pension bonds with the banks.

Orr and the banks initially reached a $220 million payoff, but bankruptcy Judge Steven Rhodes ordered the city to negotiate a better deal.

Governor activates emergency center amid storm

The governor's office says the partial activation Sunday night means that key emergency management personnel from essential state agencies will report to the center, bolstering coordination with local officials. They're available to respond to local request for assistance.

Schools across state closed today - except UM

The University of Michigan in Ann Arbor is bucking the trend across the state and staying open amid severe winter weather.

Hundreds of schools across the state canceled today's classes, including Detroit Public Schools.

Michigan State University, Western Michigan University, Eastern Michigan University, Oakland University and Wayne State University are among those that canceled classes. Snow and dangerous wind chill temperatures are cited in closing decisions.

UM says in a posting on its website that campus will be open today. The school's Flint and Dearborn campuses are closed.

The University of Michigan Health System's hospitals and health centers in Ann Arbor also are scheduled to be open Monday along with clinics in Washtenaw, Wayne and Livingston counties.

Snow collapses roof at former Lake Orion bar

Police in Lake Orion say heavy snow is believed to have caused the roof to collapse at a two-story building that once housed a bar.

No injuries were reported.

Police say no one was inside the former Wagon Wheel bar in Lake Orion about 7 p.m. Sunday at the time of the collapse. Officer David Presnell tells the Detroit Free Press that a nearby roadway was closed in case the rest of the building comes down.

Presnell says the building was to be renovated in the spring. About a foot of snow had fallen on the area by the time the roof collapsed.

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